中国中西部海相碳酸盐盆地油气资源

On Oil and Gas Resources in Marine Carbonate Basin of Central-Western China

中国陆上海相油气盆地主要分布在特提斯构造域中,自晚元古代到中生代,具克拉通基底的塔里木、鄂尔多斯和四川三大海相盆地,具有巨大的资源潜力,是当前我国重要的油气勘探、开发区。中国古大陆沉积-构造演化在加里东运动期和海西-早印支运动期,发育两个构造层次的海相盆地。早古生代海相盆地的演化与洋-陆转换共耦,沉积了海侵和海退序列的烃源岩;晚古生代—早印支运动期,早期海侵序列以储集层为主、烃源岩次之;海平面下降期的盆地具生储双重性。油气勘探开发的实践证明,三大海相盆地在生烃、聚集-成藏上具有三个共性:原型盆地演化和沉积序列相同,具五个层系的烃源岩(Z2、Э1、O1、O2-3、S1);加里东构造运动形成夭折前陆盆地,造就了古隆起和构造掀斜,形成深水盆和多期古暴露面;古岩溶碳酸盐与上覆晚古生代组成聚集成藏体系。盆地古地理迁移和构造演化的时序差决定了南、北盆地的特殊性。

The onshore marine hydrocarbon-bearing basins of China are mainly distributed in Tethyan tecton ic do-main.From Ptoterozoic to Mesozoic,marine basins like Tarim,Ordos and Sichuan with cratonic basement are of enor-mous potentials in resources.They are major areas for petroleum exploration and development in China.Two structural strata of the marine basins are developed in Caledonian movement and Hercynian-early Indo-China movement for Chi -na's old land sedimentary and tectonic evolutions.The evolution of marine basins in early Paleozoic occurred as hydro-carbon source rocks with transgressive sequence and regressive sequence;during late Paleozoic-early Indo-China move-ment,the transgressive sequence was dominated by reservoir rocks,deposited secondarily by hydrocarbon source rocks;while the deposits of the regressive sequence developed both hydrocarbon source rocks and reservoir rocks.It is shown from ex ploration and development of these basins that they have three generalities in hydrocarbon generation,accumu -lation and forming reservoirs,i.e.,the prototype basinal evolution is similar to the depositional sequences with five sets of hydro carbon source rocks(Z 2 ,Э 1 ,O 1 ,O 2-3 ,S 1 );in Caledonian movement formed failed foreland basins,deep basins and mul tistage exposed and corrosive surfaces occurred with palaeo-uplifts and structural tilting;the carbonate rocks with pale o-karst and overlapping Upper Paleozoic shaped reservoir system.The paleo-geographic migration and the time def-erence of structural evolution resulted in the diversity between northern and southern basins.